1. Field of the Invention
The present invention relates to a gripping unit which is openable and closable with respect to a treatment section of a probe, and a bipolar treatment instrument which performs treatment on a treated target gripped between the treatment section of the probe and the gripping unit.
2. Description of the Related Art
U.S. Patent Application Publication No. 2011/0278343 discloses a bipolar treatment instrument which includes a probe in which a treatment section is provided in its distal portion, and a jaw as a gripping unit which is openable and closable with respect to the treatment section and which performs treatment using a high-frequency current (high-frequency energy). The treatment section of such a bipolar treatment instrument functions as a probe-side electrode section (a first electrode section) when high-frequency energy is transmitted (supplied) through the probe. The jaw (the gripping unit) is provided with a supporting section and a swing section configured to swing with respect to the supporting section. The swing section is coupled to the supporting section with a spring serving as a coupling member being interposed therebetween in such a manner that the swing section is swingable about the swing axis parallel to a width direction of the jaw. The swing section functions as a jaw-side electrode section (a second electrode section) when high-frequency energy is transmitted (supplied) through a conductive portion provided in a sheath through which a probe is inserted and the support section of the jaw.
A jaw-side facing surface opposed to the treatment section is provided in the swing section, and when a treated target, such as living tissue, etc., is gripped between the treatment section of the probe and the jaw, the jaw is abutted to the treated target on the jaw-side facing surface of the swing section. Since the swing section in which the jaw-side facing surface abutted to the treated target is swingable about the swing axis, the force between the jaw and the treatment section to grasp the treated target in the case where the distal portion of the jaw-side facing surface (the distal portion of the jaw) is abutted to the treated target is approximately the same as the case where the proximal portion of the jaw-side facing surface (the proximal portion of the jaw) is abutted to the treated target. In other words, the gripping force between the jaw and the treatment section can be maintained nearly uniform, even when the position where the jaw-side facing surface is abutted to the treated target in a direction parallel to an extended axis of the jaw (a distal direction and a proximal direction) is changed.